Hi, I understand your problem, I don't know what the curves lowcarb diet is like, I'm on atkins. I sometimes take fiber capsules, Or use flax meal, for added fiber but for the most part my body has adjusted well. I also eat a lot of fiberous veggies. I do believe that most of the fat stored on your belly is from to many carbs. I have read a lot of books on this inc, atkins, southbeach, , You on a diet,etc. all these books blame belly fat on to many simple carbs. I would recomend, Living the lowcarb life. It has agreat explination of why carbs make us fat, and reviews a bunch of different diet plans. It is easy to read and very informative. Your local library should have it.
I hope this helps. Good luck to you. I'm sure lots of others on this board will have good advice aswell.